Lunar colonists could be in for a nasty shock — literally. A team of US scientists has found that the Moon's surface can become charged with up to several thousand volts of static electricity. This charging could release sparks that disable electronic equipment — including monitors, space buggies or even the front door of a Moon base. And it could cause dust clouds that clogs up instruments. What's worse, it can be caused by bad weather in space: just when astronauts need their equipment to give them warning and allow them to shelter from the radiation.
Genesis Findings Solve Apollo Lunar Soil Mystery Ever since astronauts returned from another world, scientists have been mystified by some of the moon rocks they brought back. Now one of the mysteries has been solved.
The record of neon from the sun in lunar soil samples was evidence for two solar gas components with distinct isotopic compositions. One has been identified as solar wind, the other as higher-energy solar energetic particles because it was found at greater depths in the mineral grains. But the latter has long been puzzling to scientists because its relative amounts were much too large compared with present-day solar fluxes, suggesting very high solar activity in the past.
Apollo solar energetic particles do not exist. Both the Genesis and Apollo isotopic variations can be quantitatively explained by the fact that the Ne22 isotope is implanted deeper than the Ne20 isotope. Moreover, these findings indicate that there is no evidence for enhanced fluxes of high-energy solar particles billions of years ago compared to today. The team's findings are reported in a paper published in the Nov. 17 issue of the journal Science.
An early, persistent problem noted by Apollo astronauts on the Moon was dust. It got everywhere, including into their lungs. Oddly enough, that may be where future Moon explorers get their next breath of air: The moon's dusty layer of soil is nearly half oxygen.
The trick is extracting it.
"All you have to do is vaporise the stuff" - Eric Cardiff of NASA's Goddard Space Flight Centre. He leads one of several teams developing ways to provide astronauts oxygen they'll need on the Moon and Mars.
Lunar soil is rich in oxides. The most common is silicon dioxide (SiO2). Also plentiful are oxides of calcium (CaO), iron (FeO) and magnesium (MgO). In total 43% of the mass of lunar soil is oxygen.
We know the Moon to be nearly without visible colour, except some silver or golden glow. Yet the Moon actually exhibits very subtle colour variation. When we enhance the colours in an extreme way, we see dark blue Maria, partly covered with brown areas, all in contrast with the bright sparkling highlands glowing from light blue to yellow. Samples taken back from the Moon surface showed that most of these subtle colour differences are due to compositional differences of surface materials. For example, differences in colour between basaltic flows may be due to the differing relative abundances of Iron and Titanium. Also colour of terrains may be due to differences in ages as there is a gradual darkening of the surface materials caused by bombardment of the Solar wind.
Credit: Johannes Schedler
The highlands are made of light coloured rock and are completely covered with overlapping impact craters, from tiny, hemispherical holes to gigantic, multi-ringed impact basins. The large number of craters suggests that the highlands represent an ancient surface, roughly 4 billion years old. Apollo 14, 15, 16, and 17, as well as Luna 20, sampled lunar highlands.
The Maria appear to be dark deposits of a volcanic rock called basalt that fill many (but not all) of the impact basins on the lunar nearside. Surprisingly, very few mare exist on the lunar farside. The Maria are clearly younger than the highlands, because they fill parts of impact basins that formed in the highlands. They are also clearly younger because their surfaces show many fewer impact craters than the highlands do. Apollo 11, 12, and 15, and Luna 16 and 24, sampled lunar Maria.
The LEAM instrument as deployed at the Apollo 17 ALSEP site (AS-17-134-20500). The central station is directly behind it, the RTG to the right of that, and the LSG to the left of the central station. Discarded pallets and trash are also visible.
An old Apollo experiment called LEAM, short for Lunar Ejecta and Meteorites, is telling researchers something new and surprising about the moon.
Every lunar morning, when the sun first peeks over the dusty soil of the moon after two weeks of frigid lunar night, a strange storm stirs the surface. horizontal electric fields along the terminator, the interface between night and day, push electrostatically charged dust across the terminator sideways.
"The dayside of the moon is positively charged; the nightside is negatively charged." - Timothy Stubbs, Solar System Exploration Division at NASA's Goddard Space Flight Centre.
The Apollo 17 astronauts installed LEAM on the moon in 1972. The experiment operated for only 620 hours. But data was gathered during the lunar night and a 150 hours of data from the lunar day before its sensors were turned off and the Apollo program ended.
NASA is using the unique capabilities of the Hubble Space Telescope for a new class of scientific observations of the Earth's moon.
Hubble's resolution and sensitivity to ultraviolet light have allowed the telescope to search for important oxygen-bearing minerals on the moon. Since the moon does not have a breathable atmosphere, minerals, such as ilmenite (titanium and iron oxide), may be critical for a sustained human lunar presence. Ilmenite is a potential source of oxygen for breathing or to power rockets.
The new Hubble observations are the first high-resolution, ultraviolet images ever acquired of the moon. The images provide scientists with a new tool to study mineral variations within the lunar crust. As NASA plans future expeditions to the moon, such data, in combination with other measurements, will help ensure the most valuable sites are targeted for robotic and human missions.
Credit nasa
This view of the lunar impact crater Aristarchus and adjacent features (Herodotus crater, Schroter's Valley rille) illustrates the ultraviolet and visible wavelength characteristics of this geologically diverse region of the Moon. The two inset images illustrate one preliminary approach for isolating differences due to such effects as composition, soil maturity, mixing, and impact ejecta emplacement. The colour composite in the lower left focuses on the 42-kilometer-diameter Aristarchus impact crater, and employs ultraviolet- to visible-colour-ratio information to accentuate differences that are potentially diagnostic of ilmenite- (i.e, titanium oxide) bearing materials as well as pyroclastic glasses. The same is the case for the image of a section of Schroter's Valley (rille) in the lower right. Bluer units in these spectral-ratio images suggest enrichment in opaque phases in a relative sense. The magenta colour indicates dark mantle material which scientists believe contains titanium-bearing pyroclastic material. The symphony of colour within the Aristarchus crater clearly shows a diversity of materials — anorthosite, basalt, and olivine. The impact crater actually cut through a mare highlands boundary with superposed pyroclastics - a unique geologic setting on the Moon! The distinctive tongue of material extending out of the crater's southeastern rim is thought to be very olivine-rich material, based on Earth-based spectra and Clementine visible and infrared imaging data. North is at the right in these images.
"These observations of the moon have been a challenging and highly successful technological achievement for NASA and the Hubble team, since the telescope was not originally designed for lunar observations. The images will inform both scientific studies of lunar geology and future decisions on further lunar exploration" - Jennifer Wiseman, program scientist for the Hubble at NASA Headquarters.
Hubble's Advanced Camera for Surveys snapped ultraviolet and visible light images of known geologically diverse areas on the side of the moon nearest Earth. These included the Aristarchus impact crater and the adjacent Schroter's Valley. Hubble also photographed the Apollo 15 and 17 landing sites, where astronauts collected rock and soil samples in 1971 and 1972.
Scientists are comparing the properties of the rock and soil samples from the Apollo sites with the new Hubble images, and the Aristarchus region, which neither humans nor robotic spacecraft have visited. The Hubble observations of Aristarchus crater and Schroter's Valley will help refine researchers' understanding of the diverse, scientifically interesting materials in the region and to unravel their full resource potential.
"Our initial findings support the potential existence of some unique varieties of oxygen-rich glassy soils in both the Aristarchus and Apollo 17 regions. They could be well-suited for visits by robots and human explorers in efforts to learn how to live off the land on the moon" - Jim Garvin, chief scientist at NASA's Goddard Space Flight Centre, Greenbelt, Md. Garvin is principal investigator for the project.
"While it will require many months before fully quantitative results can be developed, we already have evidence that these new observations will improve the precision by which we can understand materials such as ilmenite to help better inform exploration decisions" - Jim Garvin.
Hubble's lunar observation analysis team included colleagues from Goddard and Cornell University, Ithaca, N.Y.; Brown University, Providence, R.I.; North-western University, Evanston, Ill.; the University of Pittsburgh.; and the University of Hawaii, Manoa.
The Moon's soil is impregnated with nitrogen that came from Earth's atmosphere, according to Japanese scientists. The researchers, giving a new interpretative spin on analysis of lunar soil brought home by the Apollo missions, believe that the nitrogen escaped from Earth's upper atmosphere as charged atoms.
These ions then washed over the Moon, soon after Earth and its satellite were formed and were close together.
However, this could only have happened before Earth acquired its magnetic field, a phenomenon caused by a "dynamo" of liquid iron that began to circulate in the planet's core, they theorise.
The hypothesis could explain a long-running mystery about the Moon's surface.
The Moon was formed at high temperatures, and should thus be depleted in volatile elements, including nitrogen, carbon, hydrogen and the six "noble" gases, helium, neon, argon, krypton, radon and xenon.
However, all these elements have been found in the lunar soil, which suggests that the source came from elsewhere.
The paper is lead-authored by Minoru Ozima of the Graduate School of Earth and Planetary Science at the University of Tokyo.